Stator and motor comprising same

ABSTRACT

One embodiment relates to a stator unit and a motor comprising same, the stator unit comprising: a stator core; a coil wound around the stator core; and an insulator disposed between the stator core and the coil, wherein the stator core comprises a support part, and a coil winding part disposed on both side surfaces of the support part so as to protrude therefrom, wherein the support part and the coil winding part are disposed so as to form a cross shape. Accordingly, a coil space factor may be increased by using the cross-shaped stator core.

TECHNICAL FIELD

An embodiment relates to a stator and a motor including the same.

BACKGROUND ART

A motor is a device configured to obtain a rotating force by convertingelectrical energy to mechanical energy, and is widely used in a vehicle,a home appliance, an industrial apparatus, and the like.

FIG. 1 is a transverse sectional view illustrating a conventional motor2.

Referring to FIG. 1, the motor 2 can include a housing 10, a shaft 20, astator 30 disposed on an inner circumferential surface of the housing10, a rotor 40 installed on an outer circumferential surface of theshaft 20, and the like. Here, the stator 30 of the motor 2 rotates theshaft 20 by causing an electrical interaction with the rotor 40 toinduce rotation of the rotor 40. Accordingly, a driving force isgenerated in the motor 2.

Particularly, when the motor 2 is a three phase multi-pole motor, coilshaving a Phase 1, a Phase 2, and a Phase 3, respectively, are woundaround teeth of the stator 30, and since currents flow through thecoils, a rotating magnetic field is generated between the stator 30 andthe rotor 40 to rotate.

Power supplied to the three phase multi-pole motor can have threephases, and the three phase multi-pole motor can be a motor having aninverter circuit connected to single phase power to autonomously rectifysingle phase AC power to DC, and can be controlled in three phasesincluding the Phase 1, the Phase 2 and the Phase 3. Further, the threephase multi-pole motor is not limited to a particular motor, and forexample, can be an induction motor or a synchronous motor. Here, thethree phases can be referred to as a U phase, a V phase, and a W phase.

The stator 30 can include a yoke 31 and a plurality of teeth 32.Further, the teeth refer to the plurality of teeth 32.

Accordingly, a space in which the coils are wound can be formed betweenone tooth 32 and another tooth 32 disposed adjacent to the one tooth 32.Here, the space refers to a slot S.

As shown in FIG. 1, the slot S can be formed in a trapezoidal shape.Accordingly, the outside of the slot S is a large space and thus thereis no problem in winding the coils. On the other hand, the inside of theslot S is a small space and thus the coils are limited in being wound.

Particularly, when the coil has a large diameter, a case in which thecoils are not abundantly wound inside the slot S and are spatiallywasted occurs.

FIG. 2 is a view illustrating the coil wound in the slot. Accordingly,FIG. 2 shows a state of winding, disposition, and a space factor of thecoil.

As shown in FIG. 2, when a coil 33 having a diameter of 1.2 mm is woundaround the tooth 32, the number of maximum turns of the coils disposedin the slot S cab is 31. Here, an arrow shows a winding direction of thecoils 33.

In this case, insulators 34 can be disposed on the tooth 32. Theinsulators 34 insulate the tooth 32 and the coils 33.

Accordingly, it is difficult for the space factor of the coil wound inthe conventional motor 2 to be improved in the above-describedstructure.

Meanwhile, the motor can be subjected to a dual winding process in whichtwo coils are wound to realize two individual phases among a U phase, aV phase, and a W phase.

However, since in the dual winding process, second winding is performedafter first winding, two winding processes should be performed.Accordingly, productivity decreases.

Further, an insulation problem between the coil which is wound first andthe coil which is secondarily wound can occur.

DISCLOSURE Technical Problem

An embodiment is directed to providing a stator unit of which a spacefactor of a coil is improved and a motor including the same.

An embodiment is directed to providing a stator and a motor in which twowinding processes are simplified into one winding process while dualwinding may be realized.

Further, the present invention is directed to providing a stator and amotor in which a wall structure in which a groove is formed in aninsulator of the stator is used to solve an insulation problem and acoil disposed in the groove is cut to realize a dual winding structure.

Problems desired to be solved by the present invention are not limitedto the above-described problems, and purposes and effects understoodfrom solutions and embodiments which will be described below are alsoincluded.

Technical Solution

One aspect of the present invention provides a stator unit including: astator core; a coil wound around the stator core; and an insulatordisposed between the stator core and the coil, wherein the stator coreincludes a support part and a coil winding part disposed to protrudefrom both side surfaces of the support part, and the support part andthe coil winding part are disposed in a cross shape.

Preferably, the coil may be wound around the coil winding part withrespect to the coil winding part.

Further, a cross section of the coil may have a quadrangular shape.

In addition, a radius (STCR) from a virtual point (C) to a center of thecoil winding part may be obtained by the following formula,

STCR=√{square root over (((STOR ² +STIR ²)/2))}

wherein STOR is a radius from the virtual point (C) to an outer side ofthe support part, and STIR is a radius from the virtual point (C) to aninner side of the support part.

In addition, a width (W1) of the coil winding part may be 0.55˜0.65 of awidth (W2) of the support part.

Another aspect of the present invention provides a motor including: ashaft; a rotor including a hole into which the shaft is inserted; and astator disposed outside the rotor, wherein the stator is formed bydisposing a plurality of stator units along a circumferential direction,the stator unit includes: a stator core; a coil wound around the statorcore; and an insulator disposed between the stator core and the coil,the stator core includes: a support part disposed in a radial directionwith respect to a center C; and a coil winding part disposed to protrudefrom both side surfaces of the support part in the circumferentialdirection, and the support part and the coil winding part are disposedin a cross shape.

Preferably, the coil may be wound around the coil winding part withrespect to the coil winding part.

Further, a cross section of the coil may have a quadrangular shape.

In addition, a radius (STCR) from a virtual point (C) to a center of thecoil winding part may be obtained by the following formula,

STCR=√{square root over (((STOR ² +STIR ²)/2))}

wherein STOR is a radius from the virtual point (C) to an outer side ofthe support part, and STIR is a radius from the virtual point (C) to aninner side of the support part.

In addition, a width (W1) of the coil winding part may be 0.55˜0.65 of awidth (W2) of the support part.

In addition, as the plurality of stator units may be disposed in thecircumferential direction, a first slot may be formed at an outer sidewith respect to the coil winding part, and a second slot may be formedat an inner side with respect to the coil winding part.

Still another aspect of the present invention provides a statorincluding: a stator core; an insulator disposed on the stator core; anda coil wound around the insulator, wherein the insulator includes: amain body on which the coil is wound; an inner guide configured toprotrude from an inner side of the main body; an outer guide configuredto protrude from an outer side of the main body; a protruding partdisposed between the inner guide and the outer guide and configured toprotrude from the main body; and a groove formed in an upper portion ofthe protruding part.

Here, the groove may be open at an inner side surface and an outer sidesurface of the protruding part.

Further, the main body may include a first main body disposed betweenthe protruding part and the inner guide and a second main body disposedbetween the protruding part and the outer guide, and the coil may bewound around the first main body and then wound around the second mainbody after passing through the groove.

In addition, as one area of the coil is cut, the coil may be dividedinto a first coil disposed on the first main body and a second coildisposed on the second main body, and two end portions may be formed ineach of the first coil and the second coil.

In addition, each of the first coil and the second coil may include astart line and an end line.

One of the end portions of the coil formed as the one area of the coiladjacent to the groove is cut may become the end line of the first coiland the other may become the start line of the second coil.

Meanwhile, one side of the groove disposed in the inner side surface maybe disposed adjacent to a side surface of the protruding part.

In this case, the groove may be disposed to be inclined a predeterminedangle (0) based on the inner side surface.

Further, a protruding height (H1) of the protruding part may be greaterthan a protruding height (H2) of the inner guide and smaller than aprotruding height (H3) of the outer guide based on an upper surface ofthe main body.

Yet another aspect of the present invention provides a motor including:a shaft; a rotor disposed outside the shaft; a stator disposed outsidethe rotor; and a housing configured to accommodate the rotor and thestator, wherein the stator includes: a stator core; an insulatordisposed on the stator core; and a coil wound around the insulator, theinsulator includes: a main body on which the coil is wound; an innerguide configured to protrude from an inner side of the main body; anouter guide configured to protrude from an outer side of the main body;a protruding part configured to protrude from the main body; and agroove formed in an upper portion of the protruding part, and the grooveis formed from an inner side surface of the protruding part to an outerside surface of the protruding part.

Here, the main body may include a first main body disposed inside theprotruding part and a second main body disposed outside the protrudingpart based on the protruding part, and the coil may be wound around thefirst main body and then wound around the second main body after passingthrough the groove;

Further, as one area of the coil is cut, the coil may be divided into afirst coil disposed on the first main body and a second coil disposed onthe second main body, and two end portions may be formed in each of thefirst coil and the second coil.

In addition, each of the first coil and the second coil may include astart line and an end line, and one of the end portions of the coilformed when the one area of the coil adjacent to the groove is cut maybecome the end line of the first coil and the other may become the startline of the second coil.

In this case, a start line of the first coil and a start line of thesecond coil may be connected to a phase terminal or a neutral terminalwhen winding directions of the first coil and the second coil are thesame.

Further, a start line of the first coil and an end line of the secondcoil may be connected to the phase terminal or the neutral terminal whenwinding directions of the first coil and the second coil are opposite toeach other.

Meanwhile, the groove may be disposed to be inclined a predeterminedangle (θ) based on the inner side surface.

Advantageous Effects

In an embodiment, a cross-shaped stator core can be used to improve acoil space factor. Accordingly, when the motor realizes the sameperformance as a conventional motor, a size of the motor can bedecreased.

Further, since an angular coil of which a cross section can be formed ina quadrangular shape is used instead of a circular coil which isconventionally used, the free space in a slot can be maximally used.

In an embodiment, a wall structure in which a groove is formed on aninsulator of a stator can be used to solve an insulation problem and thecoil disposed at the groove is cut to realize a dual winding structure.

Accordingly, productivity of the motor can be improved by simplifying awinding process.

DESCRIPTION OF DRAWINGS

FIG. 1 is a transverse sectional view illustrating a conventional motor.

FIG. 2 is a view illustrating the coil wound in a slot of theconventional motor.

FIG. 3 is a transverse sectional view illustrating a motor according toa first embodiment.

FIG. 4 is a view illustrating a stator unit of the motor according tothe first embodiment.

FIG. 5 is a view illustrating a position of a coil winding part of thestator unit disposed in the motor according to the first embodiment.

FIG. 6A is a view illustrating a magnetic path of the conventionalmotor.

FIG. 6B is a view illustrating a magnetic path of the motor according tothe first embodiment.

FIG. 7 is a view in which the performance of the conventional motor andthe performance of the motor according to the first embodiment arecompared.

FIG. 8 is a view illustrating a motor according to a second embodiment.

FIG. 9 is a view illustrating a stator unit of the motor according tothe second embodiment.

FIG. 10 is a perspective view illustrating a stator core and aninsulator of a stator disposed in the motor according to the secondembodiment.

FIG. 11 is an exploded perspective view illustrating the stator core andthe insulator of the stator disposed in the motor according to thesecond embodiment.

FIG. 12 is a perspective view illustrating the insulator of the motoraccording to the second embodiment.

FIG. 13 is a side view illustrating the insulator of the motor accordingto the second embodiment.

FIG. 14 is a plan view illustrating the insulator of the motor accordingto the second embodiment.

FIG. 15 is a view illustrating a process in which coils are wound aroundthe stator disposed in the motor according to the second embodiment,wherein FIG. 15A is view illustrating a coil wound around a first mainbody, FIG. 15B is view illustrating a coil wound around a second mainbody through a groove, and FIG. 15C is view illustrating a coil of whichone area is cut.

MODES OF THE INVENTION

Since the present invention may be variously changed and have variousembodiments, particular embodiments will be exemplified and described inthe drawings. However, the present invention is not limited to theparticular embodiments and includes all changes, equivalents, andsubstitutes within the spirit and the scope of the present invention.

Further, it should be understood that, although the terms “second,”“first,” and the like may be used herein to describe various elements,the elements are not limited by the terms. The terms are only used todistinguish one element from another. For example, a first element couldbe termed a second element, and similarly, a second element could betermed a first element without departing from the scope of the presentinvention. The term “and/or” includes any one or any combination among aplurality of associated listed items.

When predetermined components are mentioned to be “linked,” “coupled,”or “connected” to other components, the components may be directlylinked or connected to other components, but it should be understoodthat additional components may be present therebetween. On the otherhand, when the predetermined components are mentioned to be “directlylinked,” “directly coupled,” or “directly connected” to othercomponents, it should be understood that no additional components arepresent between the above-described components.

In the description of the embodiments, when one element is disclosed tobe formed “on or under” another element, the term “on or under” includesboth a case in which the two elements are in direct contact with eachother and a case in which at least another element is disposed betweenthe two elements (indirectly). Further, when the term “on or under” isexpressed, a meaning of not only an upward direction but also a downwarddirection with respect to one element may be included.

Terms used in the present invention are used just to describe theparticular embodiments, and not to limit the present invention. Thesingular form is intended to also include the plural form, unless thecontext clearly indicates otherwise. It should be further understoodthat the terms “include,” “including,” “provide,” “providing,” “have,”and/or “having” specify the presence of stated features, integers,steps, operations, elements, components, and/or groups thereof but donot preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof.

Unless otherwise defined, all terms including technical or scientificterms used in the present invention have meanings the same as those ofterms generally understood by those skilled in the art. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Hereinafter, the embodiments will be described in detail with referenceto the accompanying drawing drawings, the same reference numerals areapplied to the same or corresponding elements, and redundant descriptionthereof will be omitted.

First Embodiment

FIG. 3 is a transverse sectional view illustrating a motor according toa first embodiment, and FIG. 4 is a view illustrating a stator unit ofthe motor according to the first embodiment.

Referring to FIG. 3, a motor 1 according to the first embodiment mayinclude a housing 1100, a stator 1200, a rotor 1300, and a shaft 1400.Here, the rotor 1300 may include a rotor core 1310 and a plurality ofmagnets 1320 disposed on the rotor core 1310.

A cylindrical housing 1100 having an opening formed in an upper portionthereof and a bracket (not shown) configured to cover the opening mayform an exterior of the motor 1. Here, the bracket may be referred to asa cover.

Accordingly, an accommodation space may be formed in the motor 1 bycoupling of the housing 1100 and the bracket. Further, the stator 1200,the rotor 1300, the shaft 1400, and the like may be disposed in theaccommodation space.

The housing 1100 may be formed in a cylindrical shape and disposed sothat the stator 1200 may be supported by an inner circumferentialsurface thereof.

The stator 1200 may be supported by the inner circumferential surface ofthe housing 1100. Further, the stator 1200 is disposed at the outside ofthe rotor 1300. That is, the rotor 1300 may be disposed in the stator1200.

Referring to FIG. 3, the stator 1200 may be formed by a plurality ofstator units 1210.

The plurality of stator units 1210 may be disposed in the housing 1100along a circumferential direction with respect to a center C of themotor 1.

Referring to FIG. 4, each of the stator units 1210 may include a statorcore 1211, coils 1212, and insulators 1213. The coils 1212 are woundaround the stator core 1211, and as shown in FIG. 4, the insulators 1213may be disposed between the stator core 1211 and the coils 1212 forinsulation.

Here, the stator core 1211 may be formed by a plurality of thin plateswhich are stacked on each other.

As shown in FIG. 4, the stator core 1211 may include a support part 1211a and a coil winding part 1211 b. Here, the support part 1211 a and thecoil winding part 1211 b may be integrally formed.

The support part 1211 a may be disposed in a radial direction withrespect to the center C. That is, the support part 1211 a having apredetermined cross sectional area may be disposed toward the center C.Further, a transverse section of the support part 1211 a may be formedin a quadrangular shape. Here, the radial direction may refer to adirection in which a radius extends.

In this case, as shown in FIG. 4, the support part 1211 a may be formedto have a predetermined width W2 based on a circumferential direction.Further, the support part 1211 a of one stator unit 1210 may be disposedto be spaced apart from the support part 1211 a of another stator unit1210.

The coil winding part 1211 b may be disposed to protrude from both sidesurfaces of the support part 1211 a. Preferably, the coil winding part1211 b may be formed to protrude in a circumferential direction from aradial direction center of the support part 1211 a.

In this case, the coil winding part 1211 b may be formed to have apredetermined width W1 based on the radial direction.

Accordingly, the support part 1211 a and the coil winding part 1211 bmay be formed in a planar cross shape.

Accordingly, as shown in FIG. 3, since the plurality of stator units1210 are disposed along the circumferential direction, the stator 1200may include a first slot S1 and a second slot S2 which are spaces inwhich the coils 1212 are wound and disposed.

The first slot S1 may be disposed at an outer side with respect to thecoil winding part 1211 b.

The second slot S2 may be disposed at an inner side with respect to thecoil winding part 1211 b.

Here, with respect to the center C, the inner side refers to a directionthat is disposed toward the center C, and the outer side refers to adirection opposite the inner side

Meanwhile, the coils 1212 may be wound around the coil winding part 1211b. In this case, the insulators 1213 may be disposed on the stator core1211. The insulators 1213 insulate the coil winding part 1211 b and thecoils 1212.

Currents may be applied to the coils 1212. Accordingly, an electricalinteraction between the coils 1212 and the magnets 1320 of the rotor1300 occurs, and thus the rotor 1300 may rotate. When the rotor 1300rotates, the shaft 1400 also rotates.

The coils 1212 may be wound around the coil winding part 1211 b. In thiscase, the coils 1212 may be wound in the radial direction with respectto the coil winding part 1211 b. For example, as shown in FIG. 4, thecoil 1212 may be wound around the coil winding part 1211 b, one area ofthe coil 1212 may be disposed in the first slot S1 and the other area ofthe coil 1212 may be disposed in the second slot S2.

A cross section of the coil 1212 may be formed in a quadrangular shape.That is, a deflection coil may be used as the coil 1212.

An example in which the cross section of the coil 1212 has aquadrangular shape is described, but the embodiment is not limited tothe above, and a deflection coil having various shapes such as atriangular shape, a pentagonal shape, a hexagonal shape, and the likemay be used to improve a space factor.

Hereinafter, a space factor of the coil 33 wound around the motor 2 anda space factor of the coil 1212 of the motor 1 will be described withreference to FIGS. 2 and 4.

As shown in FIG. 2, 31 turns of the coil 33 having a diameter of 1.2 mmare wound in the slot S with respect to a tooth 32.

In the case of the motor 1, as shown in FIG. 4, 38 turns of the coil1212 are wound by (19 turns at a left side and 19 turns at a right side)with respect to the coil winding part 1211 b. In this case, the coil1212 of the motor 1 is wound in a quadrangular coil shape having a crosssectional area the same as that of the coil 33 having a diameter of 1.2mm.

Accordingly, 7 turns of the coil 1212 of the motor 1 may be furtherwound (roughly 20%) in comparison with the coil 33 of the motor 2.

That is, the space factor of the coil wound around the stator unit 1210of the motor 1 increases roughly 20% in comparison with the space factorof the coil of the motor 2. However, in the motor 1, two windingprocesses in which 19 turns of the coil are wound at each of the leftside and the right side are performed.

Accordingly, the motor 1 has an advantage that motor torque may beincreased by 20% in comparison with the motor 2. Accordingly, the motor1 may obtain the same output while reducing a size by 20% in comparisonwith the motor 2.

Meanwhile, the width W1 of the coil winding part 1211 b of the statorcore 1211 and the width W2 of the support part 1211 a of the stator core1211 have a major function in constituting a magnetic circuit.

For example, as the dimensions of the widths W1 and W2 decrease, thecoil space factor increases, which is advantageous for the motor size.However, since a magnetic saturation phenomenon occurs in the statorcore 1211, loss may increase.

Further, as the dimensions of the widths W1 and W2 increase, the coilspace factor decreases and thus a motor size increases, but since themagnetic saturation phenomenon decreases, the loss may decrease.

Accordingly, in the design aspect of the motor 1, the dimensions of thewidths W1 and W2 which are two design parameters should be appropriatelydetermined.

Accordingly, in order to obtain a maximum effect according to the coilspace factor, the width W1 of the coil winding part 1211 b may be0.55˜0.65 of the width W2 of the support part 1211 a.

However, the above condition is effective in a motor with concentratedwindings.

Accordingly, the motor 1 may be provided with twelve stator units 1210and eight magnets 1320. Further, the motor 1 may be provided with ninestator units 1210 and six magnets 1320. Alternatively, the motor 1 maybe provided with twelve stator units 1210 and ten magnets 1320.

The rotor 1300 is disposed in the stator 1200. The shaft 1400 may becoupled to a center portion of the rotor 1300.

The rotor 1300 may include the rotor core 1310 and the magnets 1320coupled to the rotor core 1310. The rotor 1300 may be classified intothe following shapes according to a coupling method between the rotorcore 1310 and the magnets 1320.

As shown in FIG. 3, the rotor 1300 may be implemented as a type in whichthe magnets 1320 are coupled to an outer circumferential surface of therotor core 1310. In the SPM type rotor 1300, a separate can member (notshown) may be coupled to the rotor core 1310 to prevent separation ofthe magnet 1320 and increase a coupling force. Further, the magnet 1320and the rotor core 1310 may be integrally formed by double injection.

Meanwhile, the rotor 1300 may be implemented as a type in which themagnets 1320 are coupled to the inside of the rotor core 1310. In theIPM type rotor 1300, a pocket in which the magnets 1320 are insertedinto the rotor core 1310 may be provided.

The rotor core 1310 may be formed by a plurality of thin plates whichare stacked on each other. Of course, the rotor core 1310 may bemanufactured in a single core form including one cylinder.

Further, the rotor core 1310 may be formed in a form in which aplurality of pucks (unit cores) forming a skew angle are stacked.

The shaft 1400 may be coupled to the rotor 1300. When an electromagneticinteraction occurs between the rotor 1300 and the stator 1200 due tocurrent supply, the rotor 1300 rotates and thus the shaft 1400 rotates.In this case, the shaft 1400 may be supported by bearings (not shown)disposed at an outer circumferential surface of the shaft 1400.

Meanwhile, in order to maximize the coil space factor, a position of thecoil winding part 1211 b is important.

A disposing position of the coil winding part 1211 b disposed on a sidesurface of the support part 1211 a will be described with reference toFIG. 5.

Here, FIG. 5 is a view illustrating the position of the coil windingpart of the stator unit according to the embodiment, and is a view whichsimplifies the stator unit 1210 to find a condition for maximizing thecoil space factor.

In this case, the stator unit 1210 has three parameters.

As shown in FIG. 5, the stator unit 1210 has parameters which are statorcenter radius (STCR), stator outer radius (STOR), and stator innerradius (STIR). That is, the STCR shows a radius from a virtual point Cto a center of the coil winding part, the STOR shows a radius from thevirtual point C to the outer side of the support part, and the STIRshows a radius from the virtual point C to the inner side of the supportpart. Here, the virtual point C may be the center C of the motor 1 or acenter C of the shaft 1400.

Accordingly, areas S3 and S4 respectively shown as circles outside andinside the STCR will be calculated as follows:

S3(the area disposed outside the STCR)=STOR ² ×π−STCR ²×π

S4(the area disposed outside the STIR)=STCR ² ×π−STIR ²×π

Accordingly, in order to maximize the coil space factor, a formula inwhich S3 is equal to S4 should be satisfied, and may be shown as followswhen simplified (π is omitted).

STOR ² +STIR ²=2STCR ²

Accordingly, the STCR which is a radius from the virtual point C to thecenter of the coil winding part may be obtained by the followingformula.

STCR=√{square root over (((STOR ² +STIR ²)/2))}

Further, the STCR obtained by the formula shows a position of the coilwinding part 1211 b for maximizing the coil space factor. In this case,the STCR may refer to a radius with respect to the center C.

FIG. 6 is a view illustrating a magnetic path of the conventional motorand a magnetic path of the motor according to the first embodiment,wherein FIG. 6A is a view illustrating a magnetic path of the motor 2,and FIG. 6B is a view illustrating a magnetic path of the motor 1according to the first embodiment.

As shown in FIG. 6, the motor 1 is not inferior in performance to theconventional motor 2 in consideration of the formed magnetic path.

FIG. 7 is a view in which the performance of the conventional motor andthe performance of the motor according to the first embodiment arecompared. In this case, under conditions of the same number of turns (24turns), the same current (115 A), the same stack (30 mm), theconventional motor and the motor according to the first embodiment arecompared based on a motor having six poles and nine slots. In this case,in the case of the motor 1, nine stator units 1210 may be disposed.

Here, the stack refers to a thickness in a longitudinal direction, whichis an axial direction, of the shaft 1400 of the motor 1. For example,referring to FIG. 3, when a transverse section of the motor 1 is shownas an x-y axis, the stack refers to a thickness of the stator 1200 in adirection vertical to the transverse section of the motor 1.

Referring to FIG. 7, a torque value of the motor 1 rises to 3.49 Nm,which is an increase of roughly 2.3% in comparison with 3.41 Nm of theconventional motor 2.

Here, in the case of the motor 1, as described above, the coil spacefactor may further increase by increasing the number of turns of thecoil 1212.

Accordingly, the motor 1 may decrease a length of the stack in inverseproportion to the increased number of turns.

That is, the stack of the motor 1 may be determined by a stack of theconventional motor 2 (30 mm)×24 turns (the number of turns of the coilof the motor 2)/N turns (the number of turns of the motor 1).

For example, the motor 1 has a stack length decreased by roughly 1.2 mmeven when the number of winding turns of the coil 1212 of the motor 1increases one turn. Accordingly, the stack of the motor 1 may be 28.8mm.

Accordingly, the size of the motor 1 may be further decreased byincreasing the winding number of the coil 1212 even when having the sameperformance as the conventional motor 2.

Meanwhile, while a two-stage process in which the insulator 34 isinserted into the stator 30 and the coils 33 are wound around the stator30 is performed in the conventional motor 2, in the motor 1, since onlya process of inserting the stator unit 1210, on which the coils 1212 arewound, into the motor 1 is performed, a working process is simplified.Accordingly, productivity of the motor 1 may be improved.

Second Embodiment

FIG. 8 is a view illustrating a motor according to a second embodiment.

Referring to FIG. 8, a motor 1 according to the second embodimentincludes a housing 2100 having an opening formed at one side thereof, acover 2200 disposed on the housing 2100, a stator 2300 disposed in thehousing 2100, a rotor 2400 disposed inside the stator 2300, a shaft 2500configured to rotate with the rotor 2400, a bus bar 2600 disposed on thestator 2300, and a sensor part 2700 configured to sense rotation of theshaft 2500.

The motor 1 may be a motor used in an EPS. The electronic power steeringsystem (EPS) assists a steering force using a driving force of the motorto ensure turning stability and provide a quick restoring force to allowa driver to safely drive.

The housing 2100 and the cover 2200 may form an exterior of the motor 1.Further, an accommodation space may be formed by coupling of the housing2100 and the cover 2200. Accordingly, in the accommodation space, asshown in FIG. 8, the stator 2300, the rotor 2400, the shaft 2500, thebus bar 2600, the sensor part 2700, and the like may be disposed. Inthis case, the shaft 2500 is rotatably disposed in the accommodationspace. Accordingly, the motor 1 may further include bearings 50 disposedat an upper portion and a lower portion of the shaft 2500.

The housing 2100 may be formed in a cylindrical shape. Further, thehousing 2100 may accommodate the stator 2300, the rotor 2400, and thelike therein. In this case, the shape or material of the housing 2100may be variously changed. For example, the housing 2100 may be formed ofa metal material that can withstand high temperatures.

The cover 2200 may be disposed on an open surface of the housing 2100 tocover the opening of the housing 2100, that is, may be disposed on thehousing 2100.

The stator 2300 may be accommodated in the housing 2100. Further, thestator 2300 causes an electrical interaction with the rotor 2400. Inthis case, the stator 2300 may be disposed outside the rotor 2400 withrespect to a radial direction.

Referring to FIG. 8, the stator 2300 may include a stator core 2310, aninsulator 2320 disposed on the stator core 2310, and coils 2330 woundaround the insulator 2320.

FIG. 9 is a view illustrating a stator unit of the motor according tothe second embodiment, FIG. 10 is a perspective view illustrating thestator core and the insulator of the stator disposed in the motoraccording to the second embodiment, and FIG. 11 is an explodedperspective view illustrating the stator core and the insulator of thestator disposed in the motor according to the second embodiment.

The stator 2300 may be formed of a plurality of stator units.

In this case, by disposing a plurality of stator units 2300 a shown inFIG. 9 along a circumferential direction, the stator 2300 of the motor 1may be realized.

Referring to FIGS. 9 to 11, the stator unit 2300 a may include thestator core 2310, the insulator 2320 disposed on the stator core 2310,and the coils 2330 wound around the insulator 2320.

The stator core 2310 may include an arc-shaped yoke 2311 and a tooth2312. Further, the tooth 2312 may be formed to protrude from the yoke2311 to wind the coil 2330. Here, although an example in which the yoke2311 and the tooth 2312 are integrally formed is described, the presentinvention is not limited thereto.

The insulator 2320 is disposed on the stator core 2310. As shown in FIG.9, the insulator 2320 may be disposed on the tooth 2312 of the statorcore 2310 to insulate the stator core 2310 and the coils 2330. Here, theinsulator 2320 may be formed of a resin material.

Referring to FIG. 11, the insulator 2320 may include an upper insulator2320 a disposed on the tooth 2312 and a lower insulator 2320 b disposedunder the tooth 2312.

FIG. 12 is a perspective view illustrating the insulator of the motoraccording to the second embodiment, FIG. 13 is a side view illustratingthe insulator of the motor according to the second embodiment, and FIG.14 is a plan view illustrating the insulator of the motor according tothe second embodiment.

Referring to FIGS. 12 to 14, the insulator 2320 may include a main body2321, an inner guide 2322, an outer guide 2323, and a protruding part2324. When the upper insulator 2320 a is compared with the lowerinsulator 2320 b, the upper insulator 2320 a may further include agroove 2325 formed in the protruding part 2324.

The coils 2330 may be wound around the main body 2321.

The main body 2321 may be disposed on the stator core 2310 to insulatethe stator core 2310 and the coils 2330.

The inner guide 2322 supports the coils 2330 wound around the main body2321 to prevent separation of the coils 2330 to the inside.

The inner guide 2322 may be disposed inside the main body 2321. Further,the inner guide 2322 may be formed to protrude from the inner side ofthe main body 2321 in an axial direction. Here, the inside refers to adirection toward the center C with respect to a radial direction, andthe outside refers to a direction opposite the inside. Further, theaxial direction is a longitudinal direction of the shaft 2500.

The outer guide 2323 supports the coils 2330 wound around the main body2321 to prevent separation of the coils 2330 to the outside.

The outer guide 2323 may be disposed outside the main body 2321.Further, the outer guide 2323 may be formed to protrude from the outerside of the main body 2321 in an axial direction.

The protruding part 2324 may be formed to protrude from the main body2321. Further, the main body 2321 may be subdivided into a first mainbody 2321 a and a second main body 2321 b by the protruding part 2324.The first main body 2321 a is disposed between the inner guide 2322 andthe protruding part 2324, and the second main body 2321 b is disposedbetween the outer guide 2323 and the protruding part 2324.

The protruding part 2324 may be disposed between the inner guide 2322and the outer guide 2323. Further, as shown in FIG. 12, the protrudingpart 2324 may be formed in a plate shape in consideration of a spacefactor of the coil 2330. In this case, an edge of the protruding part2324 may be subjected to rounding treatment. Here, although an examplein which an embodiment of the protruding part 2324 is formed in theplate shape is described, the present invention is not limited thereto.For example, the protruding part 2324 may be formed to make an interiorspace to be disposed on the cross-shaped stator core 1211 of the motor 1according to the first embodiment.

Accordingly, the protruding part 2324 insulates a first coil 2330 awound between the inner guide 2322 and the protruding part 2324 and asecond coil 2330 b wound between the outer guide 2323 and the protrudingpart 2324. For example, the first coil 2330 a is wound around the firstmain body 2321 a, and the second coil 2330 b is wound around the secondmain body 2321 b. Referring to FIG. 13, a protruding height H1 of theprotruding part 2324 may be greater than a protruding height H2 of theinner guide 2322 and smaller than a protruding height H3 of the outerguide 2323 based on an upper surface 2321 c of the main body 2321.

Referring to FIG. 12, the groove 2325 may be concavely formed in anupper portion of the protruding part 2324. In this case, the groove 2325may be disposed to be spaced a predetermined interval from the uppersurface 2321 c of the main body 2321. In consideration of a case inwhich the coils 2330 are wound around the main body 2321, a height tothe groove 2325 based on the upper surface 2321 c should be formedgreater than a height of the coil 2330 wound around the main body 2321.Accordingly, a risk of contact between the first coil 2330 a and thesecond coil 2330 b may be minimized.

As shown in FIG. 14, the groove 2325 may be extended from the inner sidesurface 2324 a of the protruding part 2324 to the outer side surface2324 b of the protruding part 2324. That is, the groove 2325 may be openat the inner side surface 2324 a of the protruding part 2324 and theouter side surface 2324 b of the protruding part 2324.

In this case, the groove 2325 may be disposed to be inclined apredetermined angle θ based on the inner side surface 2324 a. Further,one side of the groove 2325 disposed in the inner side surface 2324 amay be disposed adjacent to a side surface 2324 c of the protruding part2324. Here, adjacency refers to disposition to be spaced a predeterminedinterval apart.

As shown in FIG. 14, a distance D1 to one side of the groove 2325disposed in the inner side surface 2324 a based on the side surface 2324c of the protruding part 2324 is smaller than a distance D2 to the otherside of the groove 2325 based on the side surface 2324 c of theprotruding part 2324.

Further, one area of the coil 2330 may be disposed in the groove 2325.In this case, an edge of the groove 2325 which meets the upper surfaceof the protruding part 2324 may be rounded to protect the coils 2330.

The coils 2330 may be wound around the insulator 2320. Further, thecoils 2330 may form a rotating magnetic field by power supply.

The coils 2330 may be subdivided into the first coil 2330 a and thesecond coil 2330 b according to disposing positions with respect to theprotruding part 2324. The first coil 2330 a is wound around an area ofthe main body 2321 between the inner guide 2322 and the protruding part2324, that is, around the first main body 2321 a. Further, the secondcoil 2330 b is wound around an area of the main body 2321 between theouter guide 2323 and the protruding part 2324, that is, around thesecond main body 2321 b.

FIG. 15 is a view illustrating a process in which the coils are woundaround the stator disposed in the motor according to the secondembodiment, wherein FIG. 15A is view illustrating the coil wound aroundthe first main body, FIG. 15B is view illustrating the coil wound aroundthe second main body through the groove, and FIG. 15C is viewillustrating the coil of which one area is cut.

Referring to FIG. 15A, the coils 2330 may be wound around the first mainbody 2321 a and then move to the second main body 2321 b by passingthrough the groove 2325.

Referring to FIG. 15B, the coils 2330 which pass through the groove arewound around the second main body 2321 b. Accordingly, the coil 2330 mayinclude two end portions.

That is, two separate winding processes are conventionally performed towind the coils 2330 around the first main body 2321 a and the secondmain body 2321 b, but as shown in FIG. 15B, in the motor 1, the coils2330 are wound around the first main body 2321 a and the second mainbody 2321 b by a single winding process using the groove 2325.

Referring to FIG. 15C, one area of the coil 2330 is cut. In this case,the area of the coil 2330 which is cut may be an area adjacent to thegroove 2325. Accordingly, since the coil 2330 is divided into the firstcoil 2330 a wound around the first main body 2321 a and the second coil2330 b wound around the second main body 2321 b, a dual windingstructure may be realized.

In this case, two end portions C1 a and C1 b of the first coil 2330 amay be disposed to be upwardly exposed. Further, two end portions C2 aand C2 b of the second coil 2330 b may be disposed to be upwardlyexposed. In addition, the end portions C1 a, C1 b, C2 a, and C2 b of thefirst coil 2330 a and the second coil 2330 b may be coupled to aterminal (not shown) of the bus bar 2600.

In this case, positions of the end portions C1 a, C1 b, C2 a, and C2 bof the first coil 2330 a and the second coil 2330 b are determinedaccording to a starting position and a winding direction of the woundcoil 2330.

For example, on the first main body 2321 a, positions of the endportions C1 a and C1 b of the first coil 2330 a are determined by aposition at which the first coil 2330 a starts to be wound and a windingdirection of the first coil 2330 a. Further, on the second main body,positions of the end portions C2 a and C2 b of the second coil 2330 bare determined by a position at which the second coil 2330 b starts tobe wound and a winding direction of the second coil 2330 b.

In this case, disposing the end portions C1 a, C1 b, C2 a, and C2 badjacent to the protruding part 2324 is optimal for coupling to theterminal of the bus bar 2600, but the present invention is not limitedthereto. For example, the positions of the end portions C1 a, C1 b, C2a, and C2 b may be changed in consideration of a design structure of thebus bar 2600.

For example, when the first coil 2330 a starts to be wound around thefirst main body 2321 a at a location adjacent to the protruding part2324, the number of winding layers of the first coil 2330 a wound aroundthe first main body 2321 a may be an even number, and when the secondcoil 2330 b is wound around the second main body 2321 b after the firstcoil 2330 a is wound around the first main body 2321 a and passesthrough the groove 2325 of the protruding part 2324, winding should bestarted at the location adjacent to the protruding part 2324 like above.In this case, the number of winding layers of the second coil 2330 bwound around the second main body 2321 b may also be an even number. Inthis case, the end portions C1 a, C1 b, C2 a, and C2 b may be disposedadjacent to the protruding part 2324. Of course, other ways of windingin addition to the above way of winding may be used.

The rotor 2400 may be disposed inside the stator 2300, and the shaft2500 may be coupled to a center portion of the rotor 2400. Here, therotor 2400 may be rotatably disposed in the stator 2300.

The rotor 2400 may include a rotor core and magnets. The rotor core maybe realized in a shape in which a plurality of plates having a form of acircular thin steel plate are stacked or in the form of one cylinder. Ahole to which the shaft 2500 is coupled may be formed in a center of therotor core. A protrusion configured to guide the magnets may protrudefrom an outer circumferential surface of the rotor core. The magnets maybe attached to the outer circumferential surface of the rotor core. Theplurality of magnets may be disposed along a circumference of the rotorcore at predetermined intervals. Further, the rotor 2400 may beconfigured as a type in which the magnets are inserted into a pocket ofthe rotor core.

Accordingly, the rotor 2400 rotates due to an electrical interactionbetween the coils 2330 and the magnets, and when the rotor 2400 rotates,the shaft 2500 rotates to generate a driving force.

Meanwhile, the rotor 2400 may further include a can member disposed tosurround the magnets. The can member fixes the magnets to preventseparation of the magnets from the rotor core. Further, the can membermay prevent the exposure of the magnets to the outside.

The shaft 2500 may be rotatably disposed in the housing 2100 by thebearing 50.

The bus bar 2600 may be disposed on the stator 2300.

Further, the bus bar 2600 may be electrically connected to the coils2330 of the stator 2300.

The bus bar 2600 may include a bus bar main body and a plurality ofterminals disposed in the bus bar main body.

The bus bar main body may be a molded product formed throughinjection-molding.

The terminals may be electrically connected to the end portions C1 a andC1 b of the first coil 2330 a or the end portions C2 a and C2 b of thesecond coil 2330 b. Here, the plurality of terminals may include aneutral terminal and a phase terminal for a U phase, a V phase, and a Wphase.

Here, each of the first coil 2330 a and the second coil 2330 b mayinclude a start line and an end line. Here, the start lines may beportions at which windings of the coils 2330 a and 2330 b start, and theend lines may be portions at which windings of the coils 2330 a and 2330b end.

Referring to FIG. 15C, one of end portions of the coil 2330 formed asthe one area of the coil 2330 adjacent to the groove 2325 is cut may bethe end line of the first coil 2330 a, and the other may be the startline of the second coil 2330 b.

As shown in FIG. 15C, the first coil 2330 a may include a start line C1a and an end line C1 b thereof, and the second coil 2330 b may include astart line C2 a and an end line C2 b thereof. However, the presentinvention is not limited thereto, and the start lines and the end linesmay be determined according to a winding direction of the first coil2330 a wound around the first main body 2321 a and a winding directionof the second coil 2330 b wound around the second main body 2321 b.

As shown in FIG. 15C, when the first coil 2330 a is wound around thefirst main body 2321 a in a clockwise direction, when viewed from acenter of the stator 2300, the end portion C1 a at a right side withrespect to the tooth 2312 may be the start line of the first coil 2330a, and the end portion C1 b at a left side with respect to the tooth2312 may be the end line of the first coil 2330 a.

Further, when the second coil 2330 b is wound around the second mainbody 2321 b in a clockwise direction, when viewed from the center of thestator 2300, the end portion C2 a at a right side with respect to thetooth 2312 may be the start line of the second coil 2330 b, and the endportion C2 b at a left side with respect to the tooth 2312 may be theend line of the second coil 2330 b.

The end portions C1 a and C1 b of the first coil 2330 a or the endportions C2 a and C2 b of the second coil 2330 b are connected to thephase terminal and the neutral terminal, respectively.

When all the winding directions are the same (all the winding directionsare a clockwise direction or a counterclockwise direction), both thestart line C1 a of the end portions of the first coil 2330 a and thestart line C2 a of the end portions of the second coil 2330 b should beconnected to the phase terminal or the neutral terminal.

Further, when the winding directions are opposite to each other (in thecase in which the first coil is wound in the clockwise direction and thesecond coil is wound in the counterclockwise direction, or in the casein which the first coil is wound in the counterclockwise direction andthe second coil is wound in the clockwise direction), both the startline C1 a of the end portions of the first coil 2330 a and the end lineC2 b of the end portions of the second coil 2330 b should be connectedto the phase terminal or the neutral terminal.

Since the sensor part 2700 may grasp a present position of the rotor2400 by sensing a magnetic force of a sensing magnet installed in arotatable interlinked manner with the rotor 2400, the rotation of theshaft 2500 may be sensed.

The sensor part 2700 may include a sensing magnet assembly 2710 and aprinted circuit board (PCB, 2720).

The sensing magnet assembly 2710 is coupled to the shaft 2500 tointerwork with the rotor 2400 and thus the position of the rotor 2400 isdetected. In this case, the sensing magnet assembly 2710 may include thesensing magnet and a sensing plate. The sensing magnet and the sensingplate may be coaxially coupled to each other.

The sensing magnet may include a main magnet disposed adjacent to a holeforming an inner circumferential surface of the sensing magnet in acircumferential direction, and a sub-magnet formed on an edge of thesensing magnet. The main magnet may be arranged in the same manner as adrive magnet inserted into the rotor 2400 of the motor. The sub-magnetis subdivided more than the main magnet and formed of many poles.Accordingly, a rotating angle may be divided more finely to be measured,and driving of the motor may become smoother.

The sensing plate may be formed of a disk-shaped metal material. Thesensing magnet may be coupled to an upper surface of the sensing plate.Further, the sensing plate may be coupled to the shaft 2500. Here, ahole through which the shaft 2500 passes may be formed in the sensingplate.

A sensor configured to sense the magnetic force of the sensing magnet ofthe sensing magnet assembly 2710 may be disposed on the printed circuitboard 2720. In this case, the sensor may be provided as a Hall IC.Further, the sensor may generate sensing signals by sensing a change ofthe N-pole and the S-pole of the sensing magnet.

Although the above-described descriptions are described with referenceto the embodiments of the present invention, it should be understoodthat those skilled in the art may be capable of variously modifying andchanging the present invention within the spirit and the scope disclosedin the claims which will be described below. Further, differencesrelated to modifications and changes should be understood to be includedin the scope of the present invention defined in the appended claims.

REFERENCE NUMERALS

1, 2: motor, 1100, 2100: housing, 1200, 2300: stator, 1300, 2400: rotor,1400, 2500: shaft, 2600: bus bar, 2700: sensor part

1. A motor comprising: a shaft; a rotor including a hole into which theshaft is inserted; and a stator disposed outside the rotor, wherein thestator is formed by disposing a plurality of stator units along acircumferential direction, the stator unit includes a stator core, acoil wound around the stator core, and an insulator disposed between thestator core and the coil, the stator core includes a support partdisposed in a radial direction with respect to a center C and a coilwinding part disposed to protrude from both side surfaces of the supportpart in the circumferential direction, and the support part and the coilwinding part are disposed in a cross shape, wherein a radius (STCR) froma virtual point (C) to a center of the coil winding part is obtained bythe following formula.STCR=√{square root over (((STOR ² +STIR ²)/2))} wherein STOR is a radiusfrom the virtual point (C) to an outer side of the support part, andSTIR is a radius from the virtual point (C) to an inner side of thesupport part.
 2. The motor of claim 1, wherein the coil is wound aroundthe coil winding part.
 3. The motor of claim 1, wherein, as theplurality of stator units are disposed in the circumferential direction,a first slot is formed at an outer side with respect to the coil windingpart and a second slot is formed at an inner side with respect to thecoil winding part.
 4. (canceled)
 5. The motor of claim 1, wherein awidth (W1) of the coil winding part is 0.55˜0.65 of a width (W2) of thesupport part.
 6. A stator comprising: a stator core; an insulatordisposed on the stator core; and a coil wound around the insulator,wherein the insulator includes a main body on which the coil is wound,an inner guide configured to protrude from an inner side of the mainbody, an outer guide configured to protrude from an outer side of themain body, a protruding part disposed between the inner guide and theouter guide and configured to protrude from the main body, and a grooveformed in an upper portion of the protruding part.
 7. The stator ofclaim 6, wherein the groove is open at an inner side surface and anouter side surface of the protruding part.
 8. The stator of claim 7,wherein: the main body includes a first main body disposed between theprotruding part and the inner guide and a second main body disposedbetween the protruding part and the outer guide; and the coil is woundaround the first main body and then wound around the second main bodyafter passing through the groove.
 9. The stator of claim 8, wherein: asone area of the coil is cut, the coil is divided into a first coildisposed on the first main body and a second coil disposed on the secondmain body; and two end portions are formed in each of the first coil andthe second coil.
 10. The stator of claim 9, wherein: each of the firstcoil and the second coil includes a start line and an end line; and oneof the end portions of the coil formed as the one area of the coiladjacent to the groove is cut becomes the end line of the first coil andthe other becomes the start line of the second coil.
 11. The stator ofclaim 6, wherein a protruding height (H1) of the protruding part isgreater than a protruding height (H2) of the inner guide and smallerthan a protruding height (H3) of the outer guide based on an uppersurface of the main body.
 12. A motor comprising: a shaft; a rotordisposed outside the shaft; a stator disposed outside the rotor; and ahousing configured to accommodate the rotor and the stator, wherein thestator includes a stator core, an insulator disposed on the stator core,and a coil wound around the insulator, the insulator includes a mainbody on which the coil is wound, an inner guide configured to protrudefrom an inner side of the main body, an outer guide configured toprotrude from an outer side of the main body, a protruding partconfigured to protrude from the main body, and a groove formed in anupper portion of the protruding part, and the groove is formed from aninner side surface of the protruding part to an outer side surface ofthe protruding part.
 13. The motor of claim 12, wherein: the main bodyincludes a first main body disposed inside the protruding part and asecond main body disposed outside the protruding part based on theprotruding part; the coil is wound around the first main body and thenwound around the second main body after passing through the groove; asone area of the coil is cut, the coil is divided into a first coildisposed on the first main body and a second coil disposed on the secondmain body; and two end portions are formed in each of the first coil andthe second coil.
 14. The motor of claim 13, wherein a start line of thefirst coil and a start line of the second coil are connected to a phaseterminal or a neutral terminal when winding directions of the first coiland the second coil are the same.
 15. The motor of claim 13, wherein astart line of the first coil and an end line of the second coil areconnected to a phase terminal or a neutral terminal when windingdirections of the first coil and the second coil are opposite to eachother.